This Booker long-listed debut novel begins with the arrival of an unexpected letter and an impulsive act. When Harold Fry, a timid man in his later years, discovers that a former friend and colleague is seriously ill, he sets out with the intention of posting her a letter but instead embarks on 600-mile walk from Devon to Berwick-upon-Tweed. He believes that in some way his journey will help his friend to live. Without maps or waterproofs and only yachting shoes on his feet, he walks and walks, while his wife Maureen waits at home; at first she is angered by what she perceives as abandonment but eventually his distance allows her emotions to resurface. She remembers her husband as he once was and everything he once meant to her.

Joyce's writing is clean and simple, at times deceptively so. There are Biblical overtones and elements of parable to Harold's story. Along the way he encounters many different people. Some are moved by his act, others bemused. At one point he attracts a growing band of fellow pilgrims and becomes the centre of a media storm. Joyce, a radio-dramatist turned novelist, is less sure-footed when attempting satire, and Harold's run-ins with film stars and assorted media folk are far less elegantly handled than her tender description of the kind Slovakian doctor who tends to Harold or the young girl in the petrol station who inadvertently makes him believe in himself.

At times the novel, with its gentle, episodic and occasionally repetitive structure, borders on the twee but Joyce rarely sugar-coats things. The story is laced with loneliness, with life's numerous small disappointments and the great grey weight of the real; the last chapters deliver a couple of unexpectedly savage emotional blows. But this is tempered with a sense of quiet celebration.

Harold never fully understands why he started his journey or all he is walking for; he just knows he must keep going. A low note of hope threads through the writing, building slowly, and the small details as much as the grand narrative delight and move: the moments of connection, the reawakening of a woman frozen by grief, the ability of people to touch one another's lives.